FOG Server CPU Requirements

[ty900000]

@george1421

Yeah, it’s just a 500GB desktop HDD I had lying around. I just blew the image to five machines this morning and it was getting about 40-50MB/s, which is what I would expect from a random read, like you said.

I’m going to turn one of our “newer” systems into a FOG beefcake server when we reimage over 20-30 machines at a time and I’ll use a RAID 10 setup.

@Quazz

Thanks for the confirmation. I’ll be beefing up our server soon with a 8 or 16 core machine with 24+ GB RAM and a RAID 10 configuration, so that should help tremendously, just with the RAID 10.

Thank you both for your help! I really appreciate it!

[george1421]

@ty900000 said in FOG Server CPU Requirements:

I’m going to turn one of our “newer” systems into a FOG beefcake server when we reimage over 20-30 machines at a time and I’ll use a RAID 10 setup.

Really if you are going to image that many systems at a time I would look at multicasting the image to the machines. That way only one data stream is sent out to all systems. You need to have a network configured to support multicasting but with FOG multicasting does work well.

I know some educational groups that will reimage an entire classroom of computers (>25) between classes using multicasting.

[ty900000]

@george1421

I am running a multicast image right now and it is super slow, <20MB/sec and declining. With the unicast with 2 computers imaging, I was getting about 6GB/sec each. I did a little Googling around it seems as if our very old, crappy Dell PowerConnect switches are probably causing the issue. I guess they can’t handle the “amount” of multicast traffic - no surprise there…

We should be getting Cisco switches soon, so I’ll have to test it with those and make sure they are configured to pass multicast traffic properly.

Thanks!

[george1421]

@ty900000 With multicast the speed of the slowest computer sets your maximum transfer rate. I can say that multicasting to 20 computers should just be slightly slower than a single unicast image.

I would have to question your unit of scale. I could understand 20MB/s and 6GB/min. At 6GB/s you would need faster than a 20GbE network.

[ty900000]

@george1421

Oh, you’re right! I meant <20MB/min for multicasting two machines and 6GB/min unicasting two machines. My bad!

[george1421]

@ty900000 wow that sux on the performance scale.

[ty900000]

@george1421

Which one sucks? The 20MB/min or the 6GB/min? Or both?

[Tom Elliott]

@ty900000 The 20MB a minute.

[ty900000]

@Tom-Elliott

Ah, yeah. It was going to take over 13 hours to blow down a 17GB image. I think it’s the crappy L2 Dell switches can’t handle … much of anything. It’s a constant battle with them.

[Tom Elliott]

@ty900000 Are the switches you have capable to be “managed”.

[ty900000]

@Tom-Elliott

Yeah, they can be managed. But, I can’t do much with them. Their documentation isn’t great and the are seriously lacking commands. I’m a CCNA, so I’m a little more used to Cisco-specific commands that do Cisco-specific things. These old PowerConnects either don’t have an equivalent or just have a very different and more difficult way of doing the same thing.

[george1421]

@ty900000 said in FOG Server CPU Requirements:

20MB/min

I would expect a single unicast image to deploy about 6GB/m on a typical solid network. 4 to 5GB/m for a multicast.

You are multicasting to devices on the same vlan as the fog server?

[ty900000]

@george1421

Cool! Yeah, I was hoping to see 4-5 GB/min. We don’t have VLANs. Not yet, at least. The Dell PowerConnect switches are old and we only use them as a L2 switch for now. They can be managed, but they lack a lot of commands and documentation. Cisco Catalysts should be coming next quarter, I hope.

[Tom Elliott]

@ty900000 If they’re used as “dummy” switches, maybe replacing them with simplified dummy switches (with GB if possible) would help improve things?

[ty900000]

@Tom-Elliott

No, they’re not “dummy” switches. They are the whole entire network backbone, sadly. They’re so old when I unplugged one that hadn’t been turned off in years and plugged it back in, it was completely dead.

[Junkhacker]

@george1421 said in FOG Server CPU Requirements:

I would expect a single unicast image to deploy about 6GB/m on a typical solid network.

is a typical network really that slow?

[Tom Elliott]

@Junkhacker Your network is fairly special man, yes that’s about average lol.

[george1421]

@Junkhacker said in FOG Server CPU Requirements:

@george1421 said in FOG Server CPU Requirements:

I would expect a single unicast image to deploy about 6GB/m on a typical solid network.

is a typical network really that slow?

Yes I still have network envy of your setup. But not everyone has all gold and chrome computers either.

[george1421]

@ty900000 I there any chance you could setup a “test” network switch to just the fog server and a few test systems to compare the multicast to unicast to. If you are multicasting across your campus you may have other underlying issues that mutlicasting is making worse (like a 100Mb link somewhere). At least using all on switch backbone you could get a better idea of speeds.

[Junkhacker]

@george1421 i don’t think my setup is really that special. it’s a gigabit network with dell clients and a used Poweredge R510 we picked up cheap for the server (perc H700 raid controller with a 24 drive array, which is probably why i have the nice speed, tbh)